The report does not show that renewable sources can meet future energy demand, or a large fraction of it. It is not that its attempt to show this is unsatisfactory; the point is that it does not offer a case; it does not attempt to show what proportion of demand could be met by renewables. It presents much evidence relevant to the issue, but this is not put together into a case which sets out reasoning leading to the conclusion that the necessary quantities could be provided, how they could be provided, and that the difficulties could be overcome. The report merely presents the results of some studies which state conclusions about renewable energy’s potential, without attempting to assess their worth. It is argued below that the main such study, on which the WG3 report relies heavily, is deeply flawed, is of little or no value and does not establish its claims.Trainer adds,
There is no critical examination of the 164 studies. There is no list of the studies enabling their examination. (There is a list which seems to be of 16 research groups carrying them out.) It is not explained how they were selected; it is said that they were not randomly selected. Were only optimistic studies selected? There is no reference to any of (the few) studies that I am aware of as having been published doubting the capacity of renewable energy to meet demand. (These include Hayden, 2004, Trainer, 2007, 2010a, Moriarty and Honnery, 2010.) A satisfactory review would have presented the details from an IPCC working group reporting on their thorough critical examination of all, or a representative selection of, the reports to determine whether their quantitative conclusions were sound or plausible and whether the difficulties had been dealt with. There is no analysis of this kind. In other words the IPCC has not carried out an evaluation of literature in the field; it has only summarised the conclusions of (a select number of) studies, with no apparent effort to check on their validity.Trainer argues that the report suffers from numerous glaring flaws, and ignores significant problems for renewable energy schemes,
there is a much bigger problem, on which the report does not comment. The greatest challenges set by variability of wind and sun concerns the gaps of several days in a row when there might be no sun or wind energy available across large regions, including continents.Trainer then documents the extent of the problem, by listing and briefly describing research studies which the IPCC renewables report ignored.
Clearly these lengthy periods of calm are not rare or of minor significance. For several days in a winter month in good wind regions there would have to be almost total reliance on some other source. The considerable capital cost implications of having a back up system capable of substituting for just about all wind capacity . . .Trainer points out the problem of redundancy with renewables,
”reliably” in this context means 95% probable and the crucial point concerns what can happen in the remaining 5% of the time, which is 17 days of the year. As the above cases show it is very likely that what can happen is the occurrence of long periods with negligible wind. Thus the probability of a loss of load event might be very low, but if and when it happens the entire wind contribution would have to be made up by some other source, and as Lenzen notes the capital cost of this provision should be accounted to the wind system.
Optimistic claims re the potential of renewable energy (e.g., Stern, 2006, The World Wide Fund for Nature, 2010, Zero Carbon Britain, 2007, Greenpeace International and European Renewable Energy Council, 2010), typically fail to recognise the need for large scale redundancy in generating capacity, caused by the fact that often one or more component systems will not be contributing much if anything. For instance, when the availability of solar energy is low, enough wind capacity (or some other source) would have to have been built to make up that deficiency. When there is little wind there would have to be on hand sufficient solar generating capacity to meet the deficit. Thus total system capital cost might be several times what at first seemed to be required.Trainer points to the problems posed by the non dispatchable nature of Wind and Solar. Both require large scale storage in order to be viable.
Again there is discussion of this issue, reviewing (superficially, some) options, but it does not help much in assessing the possibility of a global renewable energy supply system. Such a system would have to rely heavily on very large scale storage of electricity, which is not possible at present and is not foreseen. The report does not contradict this view. The formidable difficulties are recognised briefly (Chapter 8, p. 41), in a sentence which actually says it is questionable whether solutions will be found. Again the seriousness of the issue is not brought out; if very large scale storage of electricity is not possible (or affordable) then it is difficult to imagine how utopian renewable energy scenarios could be achieved. . . .This should be quite enough to demonstrate that Ted Trainer's reasoning about renewable energy runs on the same track mine does. The BNC discussion of Dr. Trainer's essay is also worth reading. John Morgan pointed to a discussion of Greenpeace propagandist Sven Teske role in selecting the studies that survey as background for the critical chapter 10 of the IPCC report. Among the studies which Teske picked out for special attention was his own Energy [R]evolution. The IPCC has more than its share of enemies, including the fanatic climate science denier, Steve McIntyre who quickly picked up on the IPCC-Greenpeace connection. McIntyre has decent research skills and quickly uncovered connections between the IPCC, Greenpeace and the Renewable Energy Industry.
Solar thermal systems are planned to have 17 hr storage. If a solar thermal power station was to b e cap able of maintaining supply through four cloudy days it would need 96 hour storage. The IEA says the cost of present solar thermal storage capacity, usually c. 6-7 hours, makes up about 9% of plant cost, so a 96 hr storage capacity would add more than the cost of another 1/5 solar thermal power stations.
However the key question here is whether solar thermal heat storage capacity could enable an entire electricity supply system to continue delivering through a four day period of no wind or sun. If wind, PV and solar thermal were each delivering one-third of supply then the storage task for solar thermal would have to correspond to 3×96 hours, multiplied again by the additional capacity to deal with peak demand. In addition solar thermal power blocks would have to be three times normal size, adding to capital costs.
Left-wing, pro-nuclear environmentalist, Mark Lynas clearly saw the implications of McIntyre's attack. The press release issued by the IPCC along with the Renewbles report stated,
Close to 80 percent of the world‘s energy supply could be met by renewables by mid-century if backed by the right enabling public policies a new report shows.Thus, the most extreme Greenpeace claims about the future effectiveness of renewables are advanced by by global headlines in stories about the IPCC report. The message that the public an policy makers are most likely to receive is that the IPCC, an august scientific organization, believes that government policies should be designed to produce 80% renewable energy by 2050, and that goal is both realistic and feasible, and is recommended by the IPCC. The implications of this impression for the OPCC are terrible. Left uncorrected they can destroy the IPCC's credibility.
Mark Lynas commented,
I don’t know about Steve McIntyre, but speaking for myself I would have been delighted had the IPCC’s Working Group 3 been able to offer a credible assessment of the potential for scaling up renewable energy – as opposed to, or in combination with, other mitigation options like nuclear, fossil fuels with CCS and so on. That Greenpeace’s “revolutionary vision” ended up headlining the whole thing is a tragedy, because – in a PR disaster any half-brained PR flack should have spotted a mile off – they have undermined the very cause they sought to promote.Lynas is hardly an enemy of renewables and indeed goes on to state.
Personally I think that 80% of the world’s energy probably could be met by renewables by mid-century – but the IPCC’s renewables report singularly fails to demonstrate that.Lynas is, of course, far to kind to renewables, as Dr. Trainer demonstrates.
In fact Dr. Trainer has asked important and valid questions about a high penetrations renewables dominated electrical systems. Those questions need to be answered before the credibility of a renewables dominated electrical system can be regarded as established. The IPCC to its discredit, allowed wholly implausible claims about future renewables effectiveness to be advanced in its name.